[NekkoDroid]

IIRC FAT32 is the only that needs to be supported for a valid UEFI implementation. So to actually have something like that alpine image work for most it does need to be limited to that.

There are also standalone EFI drivers that can be loaded by other means: https://archlinux.org/packages/extra/any/efifs/ (e.g. systemd-boot loads these if they are installed to `<esp>/EFI/systemd/drivers/`)

[actionfromafar]

I guess one could do something like put a large ext4 file image on the FAT32 partition and mount that from within Linux.